The present invention relates generally to a device for holding a liquid product and having a pump tube for dispensing incremental amounts of the product from the device. In particular, the invention relates to a pouch having a pump tube extending from the bottom of the pouch, the pouch and pump tube being installable into a mechanical dispenser which selectively squeezes the pump tube to dispense predetermined incremental amounts of the liquid held within the pouch.
The invention is particularly adapted to hold liquid soap to be installed into a self-dispensing mechanism wherein activation of a push bar or the like dispenses a predetermined amount of liquid soap out of a nozzle arranged at a bottom end of the pump tube. A mechanism for holding the pouch and tube is disclosed in U.S. application Ser. No. 07/826,065, filed Jan. 27, 1992, now U.S. Pat. No. 5,242,083, which is incorporated into the present disclosure by reference.
A number of prior art devices are known to holding liquids that include elongate cylindrical portions extending therefrom for squeezing by a dispensing mechanism. Such devices are illustrated in U.S. Pat. Nos. 4,349,133, 4,463,876, 4,546,904, 4,667,854 and 4,932,562.
In a typical structure, a pouch is provided having a pump tube extending therefrom. A check valve is usually located at a lower end of the pump tube. The check valve comprises four pieces, an upper cap having a valve orifice, a lower cap having a through aperture and a ball fittable over said orifice, and a spring for biasing the ball against said orifice. When the pump tube pressure overcomes the force of the spring, fluid passes through the orifice and out of the aperture.
The check valve is designed to prevent fluid from leaking or dripping from the pump tube. Known check valve structures are not entirely satisfactory due to their complicated structure that makes manufacturing the same time consuming. Additionally, the structure in combination with known pump tubes does not always prevent dripping.
An additional problem with known pouch and tube constructions is that the tube cannot be directly sealed to the pouch. Instead, it is necessary to use a coupler to seal the tube to the pouch.
There is therefore a need for an improved pump tube and pouch construction.